0 Likes
A view of a large diagonal stope in Nevada's Larkspur Mine, a long defunct silver mine from the late 1800s that has multiple adits, however there are two main ones that have significant workings, of which include a multitude of stopes, ore chutes, raises, & winzes, not to mention a few false floors as well that could be fatal. Here one can look up at a manway raise leading up into the heights of an impressive stope over 100 feet up where the ore vein was extracted & dropped into the nearby wooden ore chute to be hauled off when ore carts were available. The ladders look very unstable but actually they were still quite sturdy, though I didn't risk climbing all the way up. After all these years there are still wooden beams pressed up against the ceiling to prevent unexpected cave-ins. As you look at the ore chute you can see drill marks all along the wood, tallies by the miners based upon the number of filled ore carts run for the day. Both of the main adits have strong drafts of cold air which lead down large winzes to lower levels, I'm sure there's another secondary exit somewhere. Graffiti on the wall says "Shoadie is a stope cat."
A few mining terms:
Adit - A horizontal passage leading into the mine, not to be confused w/ a "tunnel", which would have an opening out the other side. Adits are sloped slightly upwards to allow for drainage of groundwater.
Crosscut - A horizontal opening that does not run along the vein. Typically a shaft will lead to crosscuts at each level that give access to drifts along the vein. Crosscuts typically run straight as an arrow through worthless rock.
Drift - A horizontal opening that runs along the vein. Typically there are many ore chutes from stopes above, and the drift will wander to follow the vein.
Level - If you follow a ladder down a shaft, you will arrive at horizontal workings every 100 feet or so, and these are called levels. The levels have a station near the shaft, and are named by the distance down the shaft.
Manway - Any kind of passage with a ladder in it could be called a manway. Shafts are divided into "compartments" and one of these is very often a manway. Sometimes the manway of a shaft is crowded with pipes and cables and such.
Ore chute - A "spout" built of wood used to load broken rock from above into waiting ore bins.
Raise - A raise is like a shaft that starts undergound and goes upwards. Typically a ladder next to an ore chute along a drift goes up a raise and gives access to a stope above.
Square set stoping (timbering) - The most expensive mode of underground mining. As ore is removed in a stope, it is replaced by a 10x10 foot lattice of 12x12 timbers. The ground was unstable here & the lattice helps protect from potential collapses. Many times the sets are backfilled with broken rock to help support the stope.
Stope - An excavation underground that actually removed whatever it was they were after. These are typically irregular in shape as they follow the ore whereever it goes. If the vein is wide and/or the rock is poor, the challenge in mining is to keep the rock supported while extracting the material in the stope.
Winze - A winze is like a vertical or inclined shaft that starts underground & connects one level down to another.
Source: Mining Terms: http://cholla.mmto.org/mines/terms.html
...